1. Field of the Invention
This invention relates to adjustable controls and more specifically to means for preventing accidental or unauthorized readjustment thereof.
2. Description of the Background Art
It is conventional in control mechanisms to provide a manipulating element for manipulation by a user to effect adjustment of the control mechanism as desired. ln one form of such control mechanism, the control is adjusted by rotation of a control shaft, with the shaft being rotated by means of a knob at the end thereof.
One example of such a control mechanism is a thermostat control mechanism, such as for use in domestic furnace control applications. In one form of such mechanism, a segmentally cylindrical knob is provided for rotation about an axis, with the rotation of the knob through its connection to the thermostat control effecting adjustment thereof for adjusted control of the operation of the furnace. It is conventional in such thermostatic controls to provide some frictional means for releasably retaining the control in the set position.
A modified form of such temperature regulation control is utilized in connection with waterbeds for regulating the means for heating the bed water to a desired temperature. Such controls are conventionally disposed adjacent the bed for facilitated adjustment by the user.
Because of the large heat sink characteristics of the large volume of water utilized in such waterbeds, a substantial amount of heat energy is required for raising the temperature of the water as desired by the user. It is conventional in such beds to adjust the temperature of the watcr to approximately room temperature, such as approximately 70.degree. F. A small change in the setting of the thermostat affects a large amount of heat energy in providing a corresponding change in the temperature and, thus, it is desirable to prevent undesired changes in the thermostat settings, such as may be caused by accidental contact with the thermostat, or as by a child playing with or tampering with the setting. In most domestic applications, children have access to the thermostat control and a substantial problem has arisen in this regard in connection with the waterbed thermostat control mechanisms of the prior art.